During the last three decades, flying discs and rings have found a variety of recreational uses. Probably the two most popular toys of these types are the flying disc described in U.S. Pat. No. 3,359,678 and sold under the registered trademark Frisbee.RTM., and the flying ring described in U.S. Pat. No. 4,560,358 and sold under the registered trademark Aerobie.RTM.. Some other devices of these types described in prior art are listed below:
U.S. Pat. No. 3,312,472--Kerr
U.S. Pat. No. 3,765,122--English
U.S. Pat. No. 3,828,466--Geiger
U.S. Pat. No. 4,045,029--Katzmark
U.S. Pat. No. 4,104,822--Rodgers
U.S. Pat. No. 4,173,839--Kovac
U.S. Pat. No. 4,174,834--De Martino
U.S. Pat. No. 4,176,843--DeWitt, Jr.
U.S. Pat. No. 4,288,942--Nicholl
U.S. Pat. No. 4,370,824--Resnicow
U.S. Pat. No. 4,516,947--Pircher et al.
U.S. Pat. No. 4,669,996--Bershak
The basic design of the Frisbee.RTM. and similar flying discs, herein referred to as Frisbee-like discs, is that of a convex/concave surface of between 20 and 30 centimeters in diameter and of approximate uniform thickness, circumscribed by a thicker rim that connects smoothly onto the periphery of the surface and extends 1.3 to 3.2 centimeters below the surface. The rim gives the edge of the disc the shape of an airfoil, and serves at least two additional purposes: during throwing, the rim serves as a gripping surface; and, during flight, the inner side of the rim together with the concave lower surface of the disc define a region of restrained air that plays an important role during the well-known hovering or stalling phenomenon that a Frisbee-like disc can be made to exhibit at the apex of its flight path. As used herein, the term hovering refers to a stalling phenomenon that occurs when a Frisbee-like disc is thrown in such a manner that the disc reaches the apex of its flight path with minimal translational energy, the energy of the disc at that point being almost entirely rotational kinetic energy and gravitational potential energy. At the point of hovering, a Frisbee-like disc seems to momentarily rest in midair before beginning to descend. When thrown over distances of 15 meters or less and at an attitude so as to produce the hovering effect, a Frisbee-like disc will invariably descend from its hovering point in a characteristic left or right banking motion.
It should be pointed out that during hovering the translational motion of a Frisbee-like disc actually ceases only instantaneously as the disc stops climbing and begins to descend. During the first second of descent, the disc drops very gradually in much the way a parachute descends, supported by restrained air (often referred to as an "air cushion") beneath its surface. However, unlike a parachute, the hovering motion of a Frisbee-like disc is unstable; the slightest air disturbance can cause the disc to slide off its trapped air cushion, resulting in the banking phenomenon.
Because air conditions immediately near the hovering point of a thrown disc are casually related to the direction a disc will descend, it is not possible for a thrower or a catcher to predict in which direction a hovering disc will bank. In games of catch between skillful and energetic players this unpredictability is part of the fun. However, this same unpredictability makes a Frisbee-like disc unsuitable for use in short-range games of catch or in target games where pinpoint landing accuracy is of primary importance.
Attempts to improve the performance of Frisbee-like discs have concentrated on reducing aerodynamic drag and on increasing aerodynamic lift in order to effect longer and straighter flights. Few, if any, attempts have been made to specifically design a disc with predictable short-range flight characteristics without regard to long-range characteristics. One possible exception is disclosed in U.S. Pat. No. 4,516,947, wherein inventors Pircher et al. disclose a "discoidal amusement device" that contains a central convex cup that these inventors claim enhances "the ability of the disc to gradually descend in a controlled fashion." The wide profile of the device disclosed by Pircher et al. suggests that their disc is useful mainly in short-to-medium range games.
The basic design of the Aerobie.RTM. and other flying rings is that of an annulus in which the ratio of the inner radius to the outer radius is 0.75 or greater. Flying rings tend to have a thin profile when viewed in cross section, being aerodynamically shaped to maximize lift and to minimize drag. Unlike a Frisbee-like disc, a flying ring is capable of straight-line flight throughout its flight path, from launching to landing, for flight distances of a few meters to many tens of meters. However, unlike a Frisbee-like disc, a flying ring has neither a flange-like outer rim nor a substantial surface area and is not able to hover in the characteristic Frisbee-like manner.
The present disclosure contemplates a new type of flying toy, one that has as its primary goal the ability to fly straight, hover, and descend vertically but gradually onto a target located directly below its hovering point for all flight distances between a few meters and approximately 15 meters. The object of the disclosure is not to improve prior art by reducing aerodynamic drag or increasing aerodynamic lift on Frisbee-like discs or on flying rings; the object is to provide an easily manufactured novel toy characterized by a predictable, gradual, stable, vertical dropping motion as the toy descends from the apex of its flight path. PG,5